The present invention relates generally to syringes for use with injectors and, more particularly, to syringes, syringe tubing and fluid transfer systems having features that improve the ease of use and efficiency of loading fluid in and ejecting fluid from the syringes.
A number of injector-actuated syringes and powered injectors for use in medical procedures such as angiography, computed tomography, ultrasound and MRI have been developed. For example, U.S. Pat. No. 4,006,736 discloses an apparatus for injecting fluid into the vascular system of a human being or an animal. Likewise, U.S. Pat. No. 4,677,980 discloses an angiographic injector and syringe wherein the drive member of the injector can be connected to, or disconnected from, the syringe plunger at any point along the travel path of the plunger via a releasable mechanism requiring rotation of the syringe plunger relative to the piston.
A front-loading syringe and injector system is disclosed in U.S. Pat. No. 5,383,858, the disclosure of which is hereby incorporated by reference. The syringes disclosed in U.S. Patent No. 5,383,858 can be securely front-loaded directly and accurately on the injector or on a pressure jacket attached to the injector, thereby facilitating the loading-unloading operation as compared to prior systems.
To load syringes with contrast fluid, a user typically connects a fill tube to the front nozzle or discharge outlet of the syringe and places the other end of the tube in a bottle or bag of contrast medium or other fluid. The plunger of the syringe is retracted (usually by means of the injector piston) to aspirate the contrast into the syringe until the desired amount is loaded into the syringe. After the syringe is filled, the fill tube is then typically discarded. Often, contrast or other fluid contained in the fill tube may drip therefrom onto the floor or the injector.
After the syringe is filled with fluid, a connector tube is connected to the discharge outlet of the syringe and the connecting tube is primed (typically by advancing the plunger in the syringe) to eject air from the syringe and the connector tube (i.e., to prevent air from being injected into the patient). While this technique is entirely effective in purging air from the tubing connected to the syringe, it is undesirable to have liquids dispensed from the end of the tube. Often, the liquids dispensed from the end of the tube foul the exterior surface of the tubing or fall onto the floor. When dealing with contrast media, this is particularly undesirable because the media is very sticky and has a tendency to migrate to whatever surface the operator touches after purging the tube.
When the patient is ready for the injection, the patient end of the connector tube is connected to, for example, a catheter, in a patient. During the time period between priming the connector tube and connecting the patient end of the connector tube to the patient, the patient end of the connector tube should be maintained in a sterile condition.
A significant amount of time and attention is required to properly load syringes with fluid and to connect and prime the connector tube. Consequently, it is very desirable to develop a new syringe or to improve existing syringes to reduce operator time and involvement in loading the syringe with fluid and/or in priming and connecting the connector tubing, while also minimizing or eliminating discharge of contrast medium or other fluid from the syringe or tubing associated with the syringe.
The present invention provides syringes, syringe tubing and a fluid transfer system that reduces the amount of time and vigilance necessary to load the syringe with fluid, such as contrast fluid, to connect the syringe to a patient and to prime the syringe and connector tube assembly. In addition, the present invention provides a purge tube that is designed to minimize leakage of contrast medium or other fluid therefrom. Further, the present invention provides a syringe and connector tube assembly operable to maintain the sterility of the connector tube for subsequent connection to a patient.
In a first aspect, a syringe includes a body and a plunger disposed therein. The body includes a nozzle formed therein and a latch connected thereto or integrally formed thereon for holding a second end of a fill tube. The first end of the fill tube is preferably pre-connected to the nozzle. A plastic or other sheath is removably disposed around the fill tube between the first and second ends to maintain the fill tube in a clean and/or sterile condition prior to use for filling/loading the syringe with contrast.
In addition, the diameter of the syringe nozzle may be enlarged to provide for increased volumetric fluid flow (and thereby faster fluid filling/loading) into the syringe. Preferably, the internal diameter of the syringe may be increased from 0.1 inches to approximately 0.2 to 0.25 inches. The enlarged syringe nozzle may also decrease the formation of air bubbles, which typically occurs during syringe filling, thereby resulting in less air needing to be expelled from the syringe and the connector tubing prior to injection and decreased risk of an inadvertent air injection into a patient.
In a preferred embodiment, the syringe is packaged with the first end of the fill tube pre-connected to the nozzle and the second end held in the latch. The sheath preferably covers the fill tube. After the syringe is removed from its packaging, the second end of the fill tube is removed from the latch and the sheath is removed from the fill tube and discarded. The second end of the fill tube is then placed in a contrast or other fluid container. The plunger of the syringe is retracted to fill the syringe with the fluid in the container. After a sufficient amount of the fluid is aspirated into the syringe, the fill tube may then be disconnected from the syringe and, preferably, discarded.
In a second aspect, a syringe includes a body and a plunger disposed therein. The body includes a nozzle formed therein and at least one hub member connected thereto or integrally formed thereon for holding an end of a connector tube. In a preferred embodiment, the at least one hub member comprises two hub members disposed on the syringe body. The connector tube includes two ends, each end being connected to a respective hub member to retain the connector tube in contact with the syringe. Preferably, the syringe and the connector tube are packaged in a pre-connected condition for ease of use by the customer.
After the syringe is filled with fluid and the fill tube is disconnected from the discharge outlet or nozzle of the syringe, one end of the connector tube is removed from a hub member and connected to the nozzle of the syringe. The second end of the connector tube is removed from the other hub member and held, preferably over a refuse or other container (i.e., to collect any fluid ejected from the connector tube during the priming operation), while the syringe and connector tube is primed to remove air therefrom. After the priming operation is completed, the second end of the connector tube is replaced on the hub member on the syringe to maintain it in a sterile condition and/or an xe2x80x9cout of the wayxe2x80x9d location until the second or patient end of the connector tube is connected to the patient.
Further, the connector tube may include one or more tethered caps to prevent the caps from being dropped on the floor or misplaced. The caps are used to close the open ends of the connector tube to, for example, prevent dust or other contaminants from entering the connector tube. After the syringe is filled and/or primed, a cap may be placed on the open, patient end of the connector tube to maintain sterility. In a preferred embodiment, the caps are tethered to the connector tube by a plastic or other member connected between each of the caps and the connector tube.
In a third aspect, a fluid transfer system includes a syringe, a fluid container and a transfer device for transferring fluid, such as contrast, from the container to the syringe to fill same. In a preferred embodiment, the transfer device includes a spike for puncturing the seal of the fluid container, a container holder for holding the fluid container on the spike, a valve for allowing fluid to enter the syringe and a syringe support member for aligning the syringe nozzle with the valve.
After the syringe is mounted on an injector, the spike of the transfer device is used to pierce the seal of the fluid container. The syringe support member of the transfer device is then placed over the nozzle of the syringe. The luer tip of the syringe nozzle engages the valve of the transfer device, thereby allowing the contents of the fluid container to flow into the syringe. To aspirate the contents of the fluid container into the syringe, the piston of the injector retracts the plunger of the syringe.
The container holder functions to maintain the fluid container in contact with the spike and the fluid transfer device as the fluid is transferred from the fluid container to the syringe. In addition, the syringe support member maintains the nozzle of the syringe aligned and engaged with the valve, which is preferably a check valve. In a preferred embodiment, the transfer system is disposable.
In a fourth aspect, a syringe includes a body and a plunger disposed therein. The body includes a nozzle formed therein. Flexible inlet tubing may be pre-connected or permanently connected to the nozzle of the syringe (or provided separately) to facilitate filling of the syringe prior to a medical procedure. The flexible tubing may remain attached to the nozzle of the syringe after filling thereof to reduce waste and the opportunity for contrast or other fluid from dripping from the syringe nozzle or the inlet tubing.
In a fifth aspect, the present invention provides a purge tube that can be connected to the end of a connector tube that delivers contrast media or other fluid to a patient. The purge tube may minimize or eliminate the discharge of contrast media from the end of the connector tube that delivers the media to the patient when the syringe and connector tube assembly is purged. In a preferred embodiment, the purge tube may collect any discharged liquid from the end of the connector tube that delivers the contrast media to the patient. The purge tube may then be removed from the connector tube and discarded to minimize or eliminate contamination of other surfaces by the liquid captured thereby.
Other aspects of the invention and their attendant advantages will be discerned from the following detailed description when read in connection with the accompanying drawings.